转玉米pepc基因的杂交水稻亲本的选育

Breeding for Parents of Hybrid Rice with Maize pepc Gene

对转玉米 pepc基因水稻进行观察研究 ,发现玉米 pepc基因不仅在水稻中高水平表达而且能稳定遗传。转基因水稻的PEPC活性比非转基因对照提高 10倍以上 ,其单株有效穗、穗总粒数、千粒重和单株产量等主要经济性状指标分别比原始亲本Kitaake提高 14 .9%、5 .7%、1.3%和 13.9%。 1998年以来 ,利用转 pepc基因水稻与杂交稻亲本杂交 ,经 5年 7代选育得出以下结果 :(1)玉米 pepc基因在新遗传背景下仍能高水平表达并能稳定遗传 ;(2 )F1的PEPC活性介于双亲之间 ,其饱和光合速率提高 5 0 % ,与双亲的差异达显著水平 ,利用高光效基因提高水稻杂种优势具有可行性 ;(3)PEPC活性与饱和光合速率呈极显著正相关 (r =0 .6 4 70 ) ,可将水稻叶片中的PEPC活性作为鉴定高光效水稻的主要生理指标 ;(4)转育成 3个较稳定的高光效水稻株系 ;(5 )建立了潮霉素催芽初选、分子标记抽检。

The investigation on transgenic rice with maize C 4 specific phosphoenolpyruvate carboxylase (pepc) gene showed that the transgenic rice plants expressed high levels of maize PEPC and the high level expression of the maize PEPC was inherited in the progenies in a Mendelian manner. The transgenic plants had activities above 10 fold higher than nontransgenic plants. As compared with nontransgenic plants, their panicle per plant, spikelet per panicle, 1000 grain weight and grain weight per plant increased by 14.9%, 5.7%, 1.3 %, and 13.9 %, respectively. The maize pepc gene was introduced into parents of two line hybrid, which are photo sensitive genic male sterile rice lines Pei'ai 64S, 2302S, 2304S and 2306S, and BT type male sterile rice line ShuangjiuA, and restorers 5129, Wanjing97, by crossing in spring, 1998. Some progress has been achieved as follows: (1) The high level expression of the maize PEPC was stably inherited in different genetic background of rice; (2) PEPC activity of F 1 hybrid was in the middle of its two parents. Its saturated photosynthetic rate raised by 50 %. The results demonstrate that it is possible to increase rice vigor by transgenic rice with maize pepc gene; (3) The activity of PEPC in leaf could be considered as the major physiological index because the correlation coefficient between PEPC activity and saturated photosynthetic rate was 0.6470 ** ; (4) Three lines of transgenic rice with maize pepc gene have been developed; (5) The technological system for selecting high photosynthetic efficiency rice has been established. It includes soaking seeds to hasten germination with solution of hygromycin phosphotransferase, marker assisted selecting the pepc genotypes by PCR analysis, investigating plant performance in field and examining PEPC activity and saturated photosynthetic rate of rice plants with maize pepc gene.